Originally Posted by
Middle_Seat
There is a difference between "not permitted" (by the airline) and "illegal" (against the law).
I don't know how reputable any of the mile buying and selling websites are. If things go wrong, your elderly relative might lose all his miles.
Yes,
illegal is a vague term that can be used narrowly to mean criminal.
Unlawful is normally used to mean in violation of a contractual or civil duty, and that describes the sale of miles.